feat(betterer ✨): allow negation of filters

jest.config.js

@@ -13,5 +13,6 @@ module.exports = {
   preset: 'ts-jest',
   testEnvironment: 'node',
   testRegex: '.*\\.spec\\.ts$',
-  watchPathIgnorePatterns: ['<rootDir>/fixtures', '<rootDir>/packages/[^/]+/src']
+  watchPathIgnorePatterns: ['<rootDir>/fixtures', '<rootDir>/packages/[^/]+/src'],
+  modulePathIgnorePatterns: ['<rootDir>/packages/extension']
 };

packages/betterer/src/suite/suite.ts

@@ -10,6 +10,8 @@ import { Defer, defer } from '../utils';
 import { BettererSuiteSummaryΩ } from './suite-summary';
 import { BettererSuite } from './types';
 
+const NEGATIVE_FILTER_TOKEN = '!';
+
 export class BettererSuiteΩ implements BettererSuite {
   private _reporter: BettererReporterΩ;
 
@@ -60,9 +62,37 @@ export class BettererSuiteΩ implements BettererSuite {
       runsΩ.map(async (runΩ, index) => {
         const lifecycle = runLifecycles[index];
 
-        const isFiltered = filters.length && !filters.some((filter) => filter.test(runΩ.name));
+        // This is all a bit backwards because "filters" is named badly.
+        const hasFilters = !!filters.length;
+
+        // And this is some madness which applies filters and negative filters in
+        // the order they are read:
+        //
+        // ["foo"] => [/foo/] => ["foo"]
+        // ["foo"] => [/bar/] => []
+        // ["foo"] => [/!foo/] => []
+        // ["foo"] => [/!bar/] => ["foo"]
+        // ["foo"] => [/foo/, /!foo/] => []
+        // ["foo"] => [/!foo/, /foo/] => ["foo"]
+        const isSelected = filters.reduce((selected, filter) => {
+          const isNegated = filter.source.startsWith(NEGATIVE_FILTER_TOKEN);
+          if (selected) {
+            if (isNegated) {
+              const negativeFilter = new RegExp(filter.source.substr(1), filter.flags);
+              return !negativeFilter.test(runΩ.name);
+            }
+            return selected;
+          } else {
+            if (isNegated) {
+              const negativeFilter = new RegExp(filter.source.substr(1), filter.flags);
+              return !negativeFilter.test(runΩ.name);
+            }
+            return filter.test(runΩ.name);
+          }
+        }, false);
+
         const isOtherTestOnly = hasOnly && !runΩ.testMeta.isOnly;
-        const isSkipped = isFiltered || isOtherTestOnly || runΩ.testMeta.isSkipped;
+        const isSkipped = (hasFilters && !isSelected) || isOtherTestOnly || runΩ.testMeta.isSkipped;
 
         // Don't await here! A custom reporter could be awaiting
         // the lifecycle promise which is unresolved right now!

packages/cli/src/options.ts

@@ -82,7 +82,11 @@ function tsconfigPathOption(): void {
 }
 
 function filtersOption(): void {
-  commander.option('-f, --filter [value]', 'RegExp filter for tests to run. Takes multiple values', argsToArray);
+  commander.option(
+    '-f, --filter [value]',
+    'RegExp filter for tests to run. Add "!" at the start to negate. Takes multiple values',
+    argsToArray
+  );
 }
 
 function excludesOption(): void {

test/cli/__snapshots__/filter-negative.spec.ts.snap

@@ -0,0 +1,137 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`betterer cli should filter tests by name with negation 1`] = `
+Array [
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+
+🌟 Betterer (0ms):
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+
+🎉 Betterer (0ms): 3 tests done!
+✅ test 1: \\"test 1\\" got checked for the first time! 🎉
+✅ test 2: \\"test 2\\" got checked for the first time! 🎉
+✅ test 3: \\"test 3\\" got checked for the first time! 🎉
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+
+🎉 Betterer (0ms): 3 tests done!
+✅ test 1: \\"test 1\\" got checked for the first time! 🎉
+✅ test 2: \\"test 2\\" got checked for the first time! 🎉
+✅ test 3: \\"test 3\\" got checked for the first time! 🎉
+
+3 tests got checked. 🤔
+3 tests got checked for the first time! 🎉
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+
+🌟 Betterer (0ms):
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+
+🎉 Betterer (0ms): 3 tests done!
+✅ test 1: \\"test 1\\" got skipped. 🚫
+✅ test 2: \\"test 2\\" stayed the same. 😐
+✅ test 3: \\"test 3\\" stayed the same. 😐
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+
+🎉 Betterer (0ms): 3 tests done!
+✅ test 1: \\"test 1\\" got skipped. 🚫
+✅ test 2: \\"test 2\\" stayed the same. 😐
+✅ test 3: \\"test 3\\" stayed the same. 😐
+
+2 tests got checked. 🤔
+2 tests stayed the same. 😐
+1 test got skipped. 🚫
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+
+🌟 Betterer (0ms):
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+
+🎉 Betterer (0ms): 3 tests done!
+✅ test 1: \\"test 1\\" stayed the same. 😐
+✅ test 2: \\"test 2\\" got skipped. 🚫
+✅ test 3: \\"test 3\\" got skipped. 🚫
+",
+  "
+   / | /     _         _   _
+ '-.ooo.-'  | |__  ___| |_| |_ ___ _ __ ___ _ __
+---ooooo--- | '_ // _ / __| __/ _ / '__/ _ / '__|
+ .-'ooo'-.  | |_)|  __/ |_| ||  __/ | |  __/ |
+   / | /    |_.__//___|/__|/__/___|_|  /___|_|
+
+🎉 Betterer (0ms): 3 tests done!
+✅ test 1: \\"test 1\\" stayed the same. 😐
+✅ test 2: \\"test 2\\" got skipped. 🚫
+✅ test 3: \\"test 3\\" got skipped. 🚫
+
+1 test got checked. 🤔
+1 test stayed the same. 😐
+2 tests got skipped. 🚫
+",
+]
+`;

test/cli/filter-negative.spec.ts

@@ -0,0 +1,55 @@
+import { startΔ } from '@betterer/cli';
+
+import { createFixture } from '../fixture';
+
+const ARGV = ['node', './bin/betterer'];
+
+describe('betterer cli', () => {
+  it('should filter tests by name with negation', async () => {
+    const { logs, paths, cleanup, runNames } = await createFixture(
+      'filter-negative',
+      {
+        '.betterer.js': `
+const { BettererTest } = require('@betterer/betterer');
+const { bigger } = require('@betterer/constraints');
+
+module.exports = {
+  'test 1': () => new BettererTest({
+    test: () => 0,
+    constraint: bigger
+  }),
+  'test 2': () => new BettererTest({
+    test: () => 0,
+    constraint: bigger
+  }),
+  'test 3': () => new BettererTest({
+    test: () => 0,
+    constraint: bigger
+  })
+};
+      `
+      },
+      {
+        logFilters: [/: running /, /running.../]
+      }
+    );
+
+    const fixturePath = paths.cwd;
+
+    const firstRun = await startΔ(fixturePath, ARGV, false);
+
+    expect(runNames(firstRun.ran)).toEqual(['test 1', 'test 2', 'test 3']);
+
+    const secondRun = await startΔ(fixturePath, [...ARGV, '--filter', '!1'], false);
+
+    expect(runNames(secondRun.ran)).toEqual(['test 2', 'test 3']);
+
+    const thirdRun = await startΔ(fixturePath, [...ARGV, '--filter', 'test', '--filter', '![2|3]'], false);
+
+    expect(runNames(thirdRun.ran)).toEqual(['test 1']);
+
+    expect(logs).toMatchSnapshot();
+
+    await cleanup();
+  });
+});